Method and apparatus for pre-conditioning metal charge materials



Apnl 27, 1965 F. w. BROOKE METHOD AND APPARATUS FOR PREP-CONDITIONINGMETAL CHARGE MATERIALS Filed Feb. 12, 1962 5 Sheets-Sheet l areINVENTOR. Frank M. Brooke 9 24AM, 1%

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METHOD AND APPARATUS FOR FEE-CONDITIONING METAL CHARGE MATERIALS FiledFeb. 12, 1962 5 heets-Sheet 2 INVENTORQ' Frank W. Brooke H/S ATTORNEYSAprll 27, 1965 F. w. BROOKE 3,180,724

METHOD AND APPARATUS FOR FEE-CONDITIONING METAL CHARGE MATERIALS FiledFeb. 12, 1962 5 Sheets-Sheet 3 r 55o 54o"]-4: L53 54b m A l lll M f" x50 o I O in m. 52 1",, 0

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METHOD AND APPARATUS FOR FEE-CONDITIONING METAL CHARGE MATERIALS FiledFeb. 12, 1962 5 Sheets-Sheet 4 Frank W Brooke H/S ATTORNEYS Apnl 27,1965 F. w. BROOKE 3,180,

METHOD AND APPARATUS FOR PRE-CONDITIONING METAL CHARGE MATERIALS FiledFeb. 12, 1962 5 Sheets-Sheet 5 Fig. I/

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l2e l2 Fig. [3 H/S ATTORNEYS- United States Patent 3,180,724 METHOD ANDAPPARATUS FOR PRE-CONDI- TIONING METAL CHARGE MATERIALS Frank W. Brooke,King Edward Apartments,

" Pittsburgh, Pa. Filed Feb. 12, 1962, Ser. No. 172,493

13 Claims. (Cl. 75-13) This invention pertains to pre-heating orpro-conditioning metal charge materials in the nature of metal scrap, orbriquettes, sponge, etc. The charge materials, and particularly ordinaryscrap metal, tend to form a somewhat heterogeneous mass or at least amass that, when placed in a container, presents considerable resistanceto the flow of hot gases therethrough. Ore briquettes or sponge may beprovided in accordance with conventional procedures by the directreduction of ore, such as iron ore.

An important phase of the invention deals with improved apparatus andprocedure for pre-conditioning metalcharges before they are introducedinto a melting furnace, such as an electric are or induction furnace.

In my Patent No. 2,804,295, I disclose apparatus which was primarilydevised for pre-conditioning scrap metal and which has served a usefulpurpose in this connection, particularly in preparing scrap charges forelectric furnace melting. However, difficulty has been encountered inproducing enough hot gas flow from the combustion chamber, particularlyat the start of the heating operation, in producing a desired type ofgas fiow, in fully anduniformly conditioning the charge, and incontrolling the operation to meet atmospheric and operating conditions.My present invention has been devised to meet the need for an improvedconstruction which will have a much longer period of operating life withminimum' maintenance, which will make practical the conditioning of awider range of metal charge materials, including 'ore reductionmaterials, which will minimize the time required for the conditioningoperation and will accomplish it in a more eflicient, complete anduniform manner as to the materials, which will enable a full andeffective control of the conditioning operation, and which will enablethe provision of charges which are preconditioned throughout and whosematerials may be conditioned to a common status prior to charging theminto or utilizing them in a melting furnace.

My present invention has been devised to meet problems heretoforeencountered in the pre-conditioning of metal charges so as to placeinduction and electric arc melting furnace installation on a bettercompetitive basis with other modern-day melting methods andparticularly, where relatively high quality metals and alloys areneeded. As pointed out in my above-mentioned patent, pro-heating ofscrap metal is not only advantageous from the standpoint of eliminatinglower melting point comtarninants including metals, oil, water, zinc,lead, arsenic, etc., but also from the standpoint of reducing the powerand heating requirements of the melting furnace as well as reducing themelting periods.

Also, as pointed out in such patent, the pre-heating of material, suchas plain carbon steel scrap, to a temperature of about 1400 F. willgreatly reduce its elastic limit and tend to make it non-magnetic. Itwill be noted that ordinary scrap metal contains much greater quantitiesof carbon steel than other metals and alloys. The first feature enablesthe compacting of the charge prior to its introduction into the meltingfurnace, while the latter feature is advantageous from the standpoint ofminimization of electric current used in an electric type of meltingoperation. The procedure developed in accordance with my presentinvention not only provides such advantages, but additionally makespossible the minimization of gaseous contaminants, such as hydrogen,nitrogen, and oxygen from the standpoint of the final melting.

The present invention has resulted from my work in endeavoring to meetthe problems heretofore encountered in pre-heating metal chargematerials. It has been devised to meet undesirable features of priorprocedure in such a manner that the field of application of preheatingmay be extended to other materials than ordinary scrap metal andfurther, in such a manner that pre-heating or pre-conditioning will bemuch more practical and enjoy a wider field of utilization.

An important factor which has heretofore limited the prior utilizationof a pre-heating apparatus was discovered to rest in difiicultiesencountered in connection with the proper support of the materialsduring the heating operation to etfect their safe transfer in apre-heating container after the completion of the pro-heating operation,to a. charging position over the open mouth of a furnace, and their safeand accurate discharge into a melting furnace.

In my earlier construction, I employed refractory-lined bottom gateswhich were held closed by winding rope around their inner ends. Thisentailed considerable difficulty, not only from the standpoint of theinitial locking of the gates and the manual operations involved, fromthe standpoint of retaining such gates locked under the intense heatinvolved without burning away the rope, but also from the standpointofcutting away the rope and discharging pro-heated material without dangerto the workmen and plant equipment, at the proper moment, into themelting furnace. Further, difficulty was encountered in connection withthe necessity for frequently replacing such gates, not'only due todamage from the charge and compacting of heterogeneous scrap materialswithin the pre-hea'ting container, but also from the standpoint, as Ihave now discovered, that heat supplied at the gates tends toconcentrate in the area of such gates and to non-positively fiow throughlarger passageways or interstices of the mass and along the outerperiphery of the mass during the pre-heating operation, rather than tosubstantially uniformly move through the mass and out to a stack througha top discharge opening of the container. Further, in this connection,the smaller the individual portions of the mass or the more compact themass is during the heating operation, the greater is this difficulty.

I have also discovered when metal charge materials are beingpre-conditioned, that heretofore there have been so-called dead or coldareas produced, due to the lack of proper, uniform, and fully eifectivecirculation of hot heating and conditioning gases through the mass. Inthis connection, I found that the manner of supplying the hot gases tothe pre-heating container, the temperature adjacent the gates whichserve as bottom supports for the material in the conditioning container,the mean temperature of the mass within the container, the

temperature of the hot gases leaving the container, and

positive flow inducing means are important in accomplishing a controland heating of the mass, such that uniformity of its conditioning iseffected, minimization of wear and tear on the pre-heating apparatus isaccomplished, and highly improved results are attained, all inaccordance with my procedure.

It has thus been an object of my present invention to solve problemsheretofore encountered in connection with the pre-heating of chargingmaterials and to broaden the practicability and scope of utilization ofa pre-heating or pre-conditioning operation for metal charges that areto be introduced into a melting furnace;

Another object of my invention has been to devise new and improvedprocedure for pro-conditioning metal charge materials and new andimproved apparatus for carrying out the procedure and meeting theproblems involved;

A further object of my invention has been to devise procedure andapparatus for meeting the heretofore disadvantageous and limitingfeatures of prior pro-heating apparatus and procedure and to accomplishpre-conditioning in an improved highly cfficient and effective manner;

A further object of my invention has been to devise pro-heatingapparatus in which a metal grate construction of improved gas flowconstruction will serve as a partible gate that will be foolproof andpositive in its action, and that can be safely and easily operated toeliminate diihculties and dangers heretofore encountered in connectionWith gates used in prior apparatus;

A further object of my invention has been to devise an improved heatingand heat transfer means that will make possible a positive, maximized,more effective, and substantially uniform upward flow of heating orconditioning gases into a conditioning chamber and through be materialmasses therein contained, and all in such a manner as to minimize wearand tear on the grate construction in its utilization and to enable animproved conditioning of the material mass or charge;

A still further object of my invention has been to devise a method ofoperation and of controlling the flow of heating gases through a mass ofcharge materials so as to effect a substantially uniform conditioning ofsuch material in a minimized time period, and in such a manner as toassure a better and more improved pre-conditioned product for furnacecharging;

These and other objects of my invention will appear to those skilled inthe art from the illustrated embodiment, the description, and theclaims.

In the drawings, FIGURE 1 is a side view in elevation and partialsection illustrating apparatus for carrying out my invention;

FIGURE 2 is a horizontal section on the scale of and taken along theline llIl of FIGURE 1; this section is taken through a hot gasgenerating combustion chamber of the construction;

FIGURE 3 is a horizontal section on the scale of and taken along theline Illlll of FIGURE 1; particularly illustrating details of theconstruction of a top enclosing hood or cover for the conditioningcontainer of my construction;

FlGURE 4 is a fragmental plan view showing details of damper or asoutflow control means utilized in the apparatus of FIGURE 1 and of areversible motor drive means for adjusting or controlling its operationor opening and closing action;

FIGURE 5 is a side elevation on the scale of FIGURE 4 showing theapparatus of such figure;

FIGURE 6 is an enlarged end or transverse section in elevation, takenalong the line VIVI of FIGURES 1 and 4, showing details of theconstruction and mounting of a butterfly damper valve Whose operatingmechanism is shown in FIGURES 4 and 5;

FlG-URE 7 is a side section in elevation on the scale of and taken inthe direction of the line VllVIl of FIGURE 6;

FIGURE 8 is a reduced somewhat diagrammatic view in elevationillustrating means for and the operation of moving the portablecontainer of FlGURE 1 to an upper aligned position with the open mouthportion of a melting furnace in preparation for charging pre-conditionedmaterials therein; in this figure, pull cable means for opening thegrate has been attached to the melting furnace;

FIGURE 9 is a view similar to and on the scale of FIGURE 8 illustratingmeans for and the operation of swingably opening the grate of thecontainer and charging the pro-conditioned materials into the meltingfurnace; in this figure, the container has been moved or raised upwardlyin alignment With the open mouth of the furnace from the position ofFIGURE 8 to swing the grate to an open position and chargepie-conditioned metal materials into the furnace;

FIGURE 10 is a top plan view on an enlarged scale with respect to andillustrating details of the construction of the grate shown in FIGURE 1;in this figure only one complementary half part of the grate is shown,

the Qt er part is of the same construction;

FIGURE 11 is an inside view in elevation on the scale of and taken alongthe line XI-XI of FIGURE 10;

FIGURE 12 is a transverse end view in elevation taken at right angles toFIGURE 11 and along the line ll-XEl of FEGURE 10;

FIGURE 13 is a transverse section in elevation on the scale of and takenalong the line XllI-Xlll of FlGURE 10;

And, FIGURE 14 is a greatly enlarged fragmental section taken along theline XIV-XTV of FIGURE 10 and illustrating the flow opening or orificeconstruction of the grate.

In carrying out my invention, 1 provide a base or heater unit A that mayhave a stationary or fixed position in the plant and that has aheat-resistant (ref-actory-lined) wall defining an under-positionedcombustion or hot gas generating chamber of circular or annular shape. Agroup of burners 25 (see FIGURE 2) are radially-positioned about theouter periphery of the unit A in a peripherally or circumterentiallyspaced-apart relationship with each other, and their flames are adaptedto impinge within the chamber. in this connection, any suitablecombustion gas mixture of air or oxygen with a combustible gas includingoil vapor, natural gas, etc. may be used for generati hot gases ofrequisite temperature for preconditio g the metal charge materials. Thecombustion chamber construction enables the hot gases, as generated, tomove about the chamber and thoroughly mix to attain a substantiallyuniform temperature.

A portable conditioning or container unit B has open top (outflow) andbottom (inflow) portions and a heatresistant (refractory-lined)container or enclosing wall in that is employed for receiving the metalcharge materials and preconditioning them therein. A cover, hood or lid49 is employed to close off the upper open end portion of the container,and conduit or duct means leads therefrom or is connected to a stack ordischarge point for cooled exhaust gases.

A partible grate 12 is swingably mounted on the container it) at thebottom open end portion thereof for positioning over the combustionchamber of the base unit A, in a substantially aligned position withrespect thereto, to receive the hot gases therefrom through orifices orflow penings therein that extend substantially over the full surfacearea thereof. The grate is of metal construction and is normallymaintained in a closed position with re spect to the bottom of thecontainer during the charging of the material thereto, during theconditioning of the material therein, and during the transfer of thecontainer to a vertically-aligned position with an open mouth of amelting furnace C.

When the container unit B has been moved, as by a conventional overheadtraveling hoist-crane, to a cooperating position with the open mouthportion of the melt ng furnace C and is properly aligned by grateoperating means with the open mouth portion, then the grate. 12 isparted or opened by an upward pulling or lifting force exerted on thecontainer (see FIGURE; 8 and 9) and its gate halves are swung upwardlyand outwardly by externally-positioned means to discharge thepreconditioned material into the furnace C.

The grate 12 not only serves as a gate to close-off the bottom of thecontainer unit B during the conditioning of the charge materials and tothus hold them in position within the enclosed chamber therein defined,but also serves as a grate or hot gas flow directingmeans to provide asubstantially uniform and highly effective flow of hot gases from thecombustion chamber into the contain er, and through the charge materialstherein.

The combustion chamber of the base or heater uni-t A is provided with acentral post (see FIGURES 1 and 2) to give additional suppont for thegrate during the conditioning of the charge when the grate is in itsclosed position, and without interfering with the substantially uniformflow of hot gases through the grate, upwardly through the chargematerials in the enclosing container 10. The cover, hood or lid 40 ischambered (see FIG- URES 1 and 3) for receiving, discharging andeffectively utilizing the gases, such that they give up a maximum amountof their heat to the charging materials within the container before theyare exhausted or discharged from the container. The gases, as thuslowered in temperature, issue or exhaust substantially centrally fromthe hood, pass along ducting and flow to a suitable stack or otherdischarge agency or point.

' During the operation of the apparatus, a constant, positive,upward-drawing force is applied to the hot gases to assure theircontinuous movement upwardly through the grate, through the chargematerials of the container, and out to the exhaust duct or dischargepoint. In the duct or conduit connections between the hood and exhaustduct 47, I have provided a sliding sleeve fitting for permitting atempering of the hot gases before they reach an exhaust fan 48.

Temperature indicating or control means, such as thermocouples, areemployed at strategic points. Control 70 is an alarm type pyrometer thatmay be set at about 1550 F. to provide a reasonably high temperature andpressure without causing damage to the grates and equipment. I havefound that a grate '12 of the construction shown (of high tensile steelalloy) will carry about 5600 pounds per square inch at about 1600 F.with a creep of 1% per 10,000 hours at such a maximum temperature. Themeans 70 is positioned adjacent the bottom of the container and theupper side of the grate, so that the supply of fuel to the burners maybe adjusted to control the generated heat for maintaining it below amaximum temperature which would damage the grate and above a minimumtemperature for maximum efiiciency in conditioning the charge materials.

A second indicating control means 71 is a dial type pyrometer toindicate average temperature of the load. It projects into the containerwall somewhat midway along its vertical extent to measure the meantemperature therein and thus, the average temperature of the loadmaterials or of the conditioning operation during the conditioningperiod. It also-indicates the temperature of the container during theidling period. Indicating control means 72 is a dial type pyrometer toenable the operator to properly set a butterfly valve or damper control50 to provide a proper back pressure and prevent a constant speed fan 48from pulling the heating gases through the load too rapidly and thus,lose the full advantage of the counter-flow economy.

When the reading of-the control means 71 is too high, .too much heat ispassing through the flow opening at the :top of the container; thebutterfly damper 50 should then be moved to more of a closing relationto set up a back pressure on the constant speed fan 48.

The means 72 is located in the outlet duct work beyond the outflowpassage from the hood 50 of the container to indicate the temperature ofthe gases leaving the container, so that the operator may control theoutflow of gases from the hood by the damper control 50 in the exhaustduct work or connections to make maximum use of retained heat of thegases before they are discharged. At the beginning of the heatingoperation, the means 72 will read room temperature and, as it rises, theoperator will close the angle of the butterfly damper 50, thereby dregulating the rate of heating and limiting heat past the fan 48.

The temperature indicated by the third means 72 is employed by theoperator to control the opening and closing of the damper valve 50, soas to open the damper when the operation is started and to graduallyclose it as the operation is continued, to assure a full, efiicient andquick conditioning of the charge materials within the conthe escape oftainer B and with a minimum loss of retained heat from Y the gasesentering the stack. For example, when the temperature of the gases forconditioning the charge are to be maintained at about l400 to 1450 F.,as a mean within the conditioning chamber of the container, then thedamper may be adjusted to provide for discharge of gases at atemperature of about 800 to 900 F.

A fourth pyrometer 73 may be a removable hand or dial type forpositioning in the duct work ahead of the fan 48, so that tempering ofthe exhaust gases with atmospheric air may be properly proportioned tolower the gases to a safe discharge temperature to the fan. It indicateshow adjustable sleeve or collar 46 should be set. The tempering of theexhaust gases by mixing with atmospheric air is governed by the readingof the fourth indicator 73 to, for example, provide them with atemperature of not greater than about 725 F. at the point where theypass through the exhaust fan 48 that is used for positively drawing thehot gasses through the conditioning unit B.

By using a contant high speed exhaust fan 48 with backwardly curvedblades in the exhaust portion of the apparatus, I assure a constant,positive drawing through of the hot gases and, in combination with asubstantially full flow supply area of the grate and other features ofmy invention, enable and provide a substantially uniform movement of thehot gases through the charge materials. In this manner, the hot gasesdisplace and sweep out insulating air or stagnant air pockets aboutportion of the charge'materials, remove moisture and other contaminants,and heat all the materials up to the desired conditioning temperature.

Further, in accordance with my invention, and as particularlyillustrated in FIGURES 8 and 9 I provide a partible grate 12 fornormally closing-off the open bottom end portion of the conditioningcontainer 10 that is swingably mounted and balanced thereon in such amanner as to normally urge the grate towards and maintain it in a closedposition to retain the metal charge materials within the container. Theconstruction is such that the closing-01f action or force is increasedwith the weight or mass of the metal charge materials.

The partible grate 12 is of reinforced construction and has projectinglifting lug portions 16 which cooperate with lifting means, such asmetal cables (chains) 30 that are removably latched or connected withthe furnace C to accurately align the container unit B in a chargingposition with respect thereto (see FIGURE 8). The grate 12 is actuatedby raising the container unit B relative to the open mouth of thefurnace C (see FIGURE 9), so as to accomplish a discharging operation ina positive manner by cooperation between the melting furnace and thecontainer. It is thus apparent that the opening of the partible grate 12cannot be accidentally effected, must be positively effected, and canonly be so effected when the portable conditioning unit or container Bis in a full charging position with respect to the furnace. Thisprovides a highly safe arrangement which can be accomplished remotelywithout any danger to the operating personnel of the plant.

With particular reference to the drawings, I have illustrated theconditioning or container unit B as having i; ials (load) introducedtherein through its open top end portion.

The partible grate 12 is illustrated as having two opposed andcomplemenetary partible halves or portions of identical construction,see particularly FIGURES l and 10. When the grate 12 is in its closedposition of FIG- URE 1, it curves centrally-downwardly-inwardly to forma dished or cup-like shape for supporting the metal charge materialswithin the container 1 The orifices in the swinging gate construction ofmy invention are highly important or critical in attaining the improvedresults. The width distribution and total area of the orifices controlthe rate of heating and the overall efficiency. Care should be taken inloading the lower layers of a charge, as small pieces of scrap canbecome jammed in the orifices in such a way that they may stand up abovethe clearance and prevent proper opening of the gate halves. It will berecognized that metal scrap is the most heterogeneous item that theelectric melting field has to handle. Such a hazard can e easily ealtwith by setting aside about to 39% of the scrap that does not containturnings, wire clippings, small plate clippings, and the like, andcharging such scrap first as a lower layer. Then, practically any typeof scrap may be added, avoidin exceptionally bad shapes that will andcause voids. At the beginning of each day, the gate, when relativelycool, may be examined to assure that the orifices are clear. In thiscountry there is always a small percentage of scrap which should behand-charged at the end of any charging period.

Another important feature of the construc"on of the gate is that eachpart swings on its own independent pivot or swing axis and, in such amanner, that if one should become stuck the other one will erntpy thepreheating container.

As shown particularly in FIGURES l, 8, and 9, each part of the grate 12has a pair of upwardlyrojecting and transversely-opposed swing arms 13'which are secured by suitable means, such as weld metal, to an uppercylindrical or annular flange portion 120 thereof. As shown, the swingarms 13 on each side of the unit B are of reinforced construction and,at their upper ends, are pivotally or swingably mounted by pins E4 on areinforcing mounting plate 15. There are a air of mounting plates 15 onopposite sides of the metal plate wall 11a of the container ll) that aresuitably secured thereto, as by weld metal. It will be noted that eachplate member 15 supports a side pair of swing arms 13 which constituteswing 7 arms for one side of the partible portions or halves of thegrate 12. Each gate half swings on its own independent pivot, so thatone becomes stuck, the other may be used to empty the container 1%.

As shown particularly in FEGURE 10, the two halves of the partible grate1.2 are of somewhat cupped or Sfillcircular section and havecomplementary inner planar edges 12b which are adapted to cooperate witheach other to, when they are in a closed position, define a struc turethat is of substantially cupped, dished or concave shape upwardlythereof. As shown particularly in FlG- URE l, the top flange portion 12aextends upwardly in a spaced relation with the lower perimeter orboundary of the container 19 and about the metal shell Ha, to provide anedge seal therewith. The outwardly-projecting lift lugs 16 have eyeletsto receive books 33 of the metal cable or chain) 39 and are secured ormounted on each half of the grate 32 for utilization, as shownparticularly in FZGURES 8 and 9.

As shown particularly in FIGURES 10 to 13, each half of the grate 12 isprovided with short, outer, radiallyinwardly-extending andperipherally-spaced-apart, reinforcing ribs lZc, that extend from theflange 12a and are connected to a radially-inwardly-spaced, curved,semicircular reinforcing rib 12d. A pair of transversely spaced-apart,longitudinally-extending reinforcing ribs lZe are connected at theirouter ends to the curved rib 12d and centrally, to a centrally-disposed,radial or cross-extending transverse rib 12]. The inner planar edge 12])of each grate half has a reinforcing rib 12g that is connected to theopposite ends of the curved rib A centrallydisposed, semi-circular rib1211 is connected at its ends to inner ends of the planar rib 12g.

A semi-annular or circular, substantially horizontal, planar bottomflange 17, about the outer periphery of the grate halves, provides anannular positioning flange for the grate when the unit B is positionedor resting on the s In the spacing between the reinforcing ribs, 1 haveprovided fiow orifices or elongated grate open portions 18 for flowingor by-passing hot gases upwardly therethrough. The o en portions 18, asshown particularly in FIGURE 10 and the cross sectional detail of FIG-14, have a cross-section of upwardly-converging frusto-conical shape orbore a from the bottom face of the grate l2 and, adjacent the upper facethereof, of circular or uniform shape or bore b. This provides floworifices in which the hot gases flowing upwardly through the grate 12,are first restricted to provide velocity streams by shape or bore a andare then flowed, Without furr restriction, and in a uniform path alongthe wall shape or bore b into the bottom of the container 16.

it will be also noted that the orifice or flow passageway portions 18are distributed substantially uniformly throughout the transverse andlongitudinal area of the grate 12 to provide an overall or asubstantially uniform supply and how of the gases upwardly therethrough.As distinguished from a peripherally-segregated area of flow, this ishighly advantageous in my construction from the standpoint of providinga full flow area beneath the metal charge materials and away from theperipheral or outer limits thereof, within the enclosing chamber definedby the container .lll. This construction, in combination with theutilization of means for providing a positive fiow of the hot gases,provides a substantially uniform type of conditioning action upwardlythrough the full extent of the mass of the materials within thecontainer 19 and prevents leaving of cold and unconditioned spots andareas,

articularly in the central portion of the mass. It further assures amaximum efficiency and effectiveness of conditioning and heating thematerials between their interstices and such that heat of the gases isquickly transferred thereto, and such that the gases exhausted from thehood of the container it) are of a relatively low temperature. Themaximum effectiveness of use of the heat of the gases is further assuredby the construction of the hood (see FIGURES l and 3) and by controllingor proportioning the throat through which the outflow of the exhaustgases is effected from the hood 4% or" the container unit B into theduct work.

The base unit or heater A has an outer metal shell wall Zia and an innerrefractory or heat-resistant wall 2% and is adapted to rcrnovablyreceive and position the unit B during the period of pre-conditioningthe metal charge materials therein, and to provide for raising andlowering the unit B into and out of a cooperating hot-gasreccivingposition with respect thereto. As shown particularly in FlGURES l and 2,the combustion or base unit A has an inner combustion chamber definedand enclosed by the walls Ztla and 26b. The upper portion of the metalshell wall 26a is provided with an angle piece 21 whose upper flangedefines a sealing and supporting flange to cooperate with and abuttinglyreceive the horizontal flange 17 of the partible grate 12.

It will be further noted that the refractory wall 2% has a central postZvlc that projects upwardly in alignment with a closed, central,circular, support and distribution portion 1 for the ribs of planar topsurface, as defined by the flanges 1% of the grate 12, to thus provide asafety support for the grate. However, it will be noted that ordinarily,as shown in FIGURE 1, there is a slight clearance spacing between thecentral post portion c and the flanges 12h so as to permit expansion andcontraction of the grate within prescribed limits.

As illustrated in FIGURES 1 and 2, the unit A is shown provided with agroup of burner units at peripherally spaced locations thereabout tosupply hot combustion gases to its chamber. The arrangement is such thatthe gases reach a substantially uniform temperature in the circular orannular chamber and become thoroughly mixed before being drawn or raisedup through the grate 12. Each burner unit 25 has an air supply opening25a and a fuel supply pipe 2517. In this connection, a suitable fuel,such as natural gas, may be supplied to the pipes 25b of the units 25 bya common header 26 and a main supply pipe or source 27, as controlled bya shut-off and flow control valve 28. A suitable combustion gas mixtureis provided in mixing chamber 2c for the flame which issues from aninwardly-diverging open-end bore 25d.

In accordance with my invention, as previously indicated, the swingablemounting of the parts of the grate 12 on the container 10 is such thatsuch parts are normally urged to the closed position of FIGURE 1, andthat the weight or mass of the materials being conditioned willcontribute to or enhance such closing action. The halves of the grate 12can only be moved or swung to their radial-outward and upward openpositions by positive pulling force action, as'efifected in the mannershown in FIGURES 8 and 9. In this connection, as illustrated, the pairof side cables are interleaved over a pair of side pulleys 31. Eachpulley 31 is rotatably carried on an outwardly-projecting mount 32secured on the metal wall 11a, adjacent the upper end of the container19. The hook 33 on the inner end of each cable 3% is adapted to latchwithin one lug I6 of the gate 12; a hook 34 at its opposite end isadapted to engage within one lug 35 that is mounted on the meltingfurnace C. It will be noted that the pair of lugs 35 as well as the pairof lugs 1.6 have a diametrically-opposed relationship. A metal bandingrim structure 36 is shown secured about the open delivery end portionand on a metal shell wall 37 of the furnace I C. This rim structure 36carries the lugs 35.

The container 10 of the unit B is shown provided with a U-shaped liftinghandle or bracket 38 which, at its lower ends, is pivotally mounted at38a for swingable positioning on the metal wall 11a. As shown in FIGURE1, a stop 11d positions the handle 38 in a downwardlydeclining positionwhen not in use to facilitate its engagement by a hoist or crane hook 39(see FIGURE 8). Thus, the hook 339 of a conventional overhead travelingcrane hoist may be employed to lift the complete unit B from thecombustion unit, heater or base A to a position in alignment with themelting furnace C and, at which time, the hooks 34 are engaged with thelugs 35 to not only align the container unit 10 with the furnace C, butalso to enable the opening of the grate 12 by then relatively raisingthe unit 10 with respect to the furnace C, as shown particularly inFIGURE 9. In this manner, the pro-conditioned charge is then directlyfed or charged into the melting furnace C. After such charging, thehooks 34 are then disconnected so that the parts of the grate 12 returnto their normal closed positions.

With particular reference to FIGURES 1 and 3, the shell wall 11a of thecontainer B is provided with an annular, planar, top seating flange 110which is adapted to define a slide-fit, sealing edge and support for anopposed, annular, sealing flange 41c of the cover, hood or lid 40. Thehood 4% has an outer metal shell wall 41a and an inner heat-resistant orrefractory Wall 411) that defines an upper, gas-receiving chamber abovethe conditioning unit B, when the hood and the unit are in a cooperatingaligned position, such as shown in FIGURE 1, and during the conditioningof metal charge materials within the container 10.

The hood or lid 40 has a metal bottom plate part or baffle member 42(see also FIGURE 3) which is provided with a central gas-bypass open orport portion 42a therethrough, a surrounding central annular orcylindrical sector portion 42b that serves as a central bafliing andthat is of upwardly-concave shape, and an outer horizontal or planarplate portion 42c connected to the portion 42b and to the seating flange41c. A series of elongated and peripherally-spaced passageway or openportions 42d are provided in the outer plate portion 42c for bypassinggases upwardly into the chamber of the hood at in combination with thecentral open portion 42a. The metal bottom plate structure baflle member42 is of integral construction and is secured at its outer peripheraledges, as by weld metal, to the seating flange 410. The baffling thusprovided assures a maximum utilization of the hot combustion gaseswithin the conditioning chamber of the container 10 before they enterthe chamber of the hood 40.

The upper end of the hood 40 is provided with an exhaust collar oroutlet pipe 43 (see FIGURE 1) which has a top flange defining aslidable-sealing fit with a bottom flange of a primary exhaust duct orconduit 45. The duct 45 has a vertical downstream portion 45a, anintermediate, horizontal, outwardly-projecting portioni 45b within whichthe indicator means 72 and the damper are operatively positioned, andhas a vertical upstream or upper end portion 450 that projects at itsupper end in a spaced relation within the downwardly-diverging orflared, annular inlet flange or skirt portion 46a of adjustable collaror sleeve 46 that is slidably-adjustably mounted on a lower end portionof a secondary, vertical exhaust duct or conduit 47. Atmospheric air, asindicated by the arrows 0, may enter the vertical duct 47 between theportion 45c and the inlet flange 46a to mix with and cool the exhaustgases that are entering the conduit 47 to protect the exhaust fan 48.

A constant speed, back-pressure-providing, unidirectional exhaust fan48, such as shown in the Garden City Fan Company catalog 565A, may beemployed in this connection, see particularly the Class II constructionof page 4 of such catalog. The fan 48 is provided with an electricdriving motor 49 and an on and off push button switch 84} forcontrolling its energization. The motor 49 will be operated to drive thefan 48 at a constant speed during the full period of conditioning ofcharge materials within the conditioning unit B. A three horsepowermotor, for a ten foot diameter conditioning container 10, has been foundsatisfactory for operating this fan at its constant speed to, not onlypositively draw off the exhaust gases through the duct'45 from the hood43, but to also draw in tempering atmospheric air 0 through the annularpassageway between the duct portion 450 and the flange or skirt portion46a.

Referring particularly to FIGURES 4, 5, 6, and 7, I have illustrated asuitable butterfly type of damper or gas flow valve construction or unit50 for controlling the flow of exhaust gases from the conditioning unitB and provide variable degrees of back pressure. The damper unit 50comprises a flanged section or segment of conduit 51 which is securelyconnected between the horizontal portion 451) (as by flanges and bolts)and the upper end portion 450 of the conduit 45, and which carries asubstantially cylindrical damper or valve plate 52. The damper plate 52is provided with a central axis shaft 53 which is secured thereto toextend thereacross through rotatable mountings 54a and 54b at opposedends of the conduit segment 51.

One end of the shaft 53 extends through a side sector plate 55, seeFIGURES 1, 6, and 7, that is secured to the one side of the conduitsegment 51 and that has a curved guide slot 55a. A swing arm 56 is atone end keyed or secured to the projecting end portion of the shaft 53and has a guide cam 57 mounted thereon, adjacent to and in a spacedrelation from the shaft 53, to move along the guide slot 55a of thesector plate 55 and control the amount of opening and closing of theplate 52 "11 fit with respect to the conduit sector 51. In the positionshown in FIGURE 7, the plate 52 fully closes oil gas flow through theduct or conduit and, when it is swung to a horizontal position in suchfigure, along the slot 550:, it is fully open to fluid flow. Betweensuch extreme upper and lower positions of the cam 57 in the slot 55552,the plate valve or damper plate 52 provides a desired control of theflow of exhaust gases through the conduit sector 51 and thus, out of theconduit 4-5 into the stack duct or conduit 43.

A second or operating lever arm 6%? is at its inner end keyed or securedon the other end of the shaft 53; and, at its extending end, ispivotally connected to a headed pin 62:: of a swivel 62 and by clampingjaws of the swivel so to one end of a connecting rod 63. A second swivel'64 has clamping jaws secured on the other end of the connecting rod asand carries a crank pin that pivotally or rotatably projects into theouter end portion of a crank 65. The inner end of the crank 65' issecured on the shaft of electric motor 66, so that actuation of themotor 66 may be employed for moving the damper valve plate 52 betweenits fully open and closed positions within the conduit sector 51, ascontrolled by the guide slot portion 55a of the sector plate 55.

After the charge materials have been conditioned in the container 1%),the hood may be moved out of a cooperating closing-olf relation with theopen top end portion of the container by suitable means, such as a swingarm mounted on a post or upright as disclosed in my Patent No.2,804,295. In this manner, the hood or lid id can be swung into and outof a closing-off relation with the container til, between the top flangelie of the container and the bottom flange of the duct portion Suchmeans is not a part of my present invention, and it will be apparent tothose skilled in the art that any suitable apparatus may be employed inthis connection. Further, after the hood has been swung away from thecontainer, if desired, the conditioned charge materials may be compactedby m ans, such as disclosed to the rightof PEGURE l or" the drawings ofpatent, and before the charge materials are fed to the melting furnaceC.

In FIGURE 1, l have shown an upright mount or post 75 on which aninstrument panel 76 is mounted. Although not shown, indicating gaugesfor the indicators 7' 7, 71, 72:, and 73 may be positioned on the panel7d for convenient reading by the operator.

Also, as shown in FIGURE 1, the motor 4% for actuating the fan 48 isener ized by a suitable electric source E that has one lead directlyconnected through panel terminal 810 and cable 32 to motor terminal 49::and that has its other lead indirectly connected to motor terminal 4%through push button switch 8%, panel terminal 815 and cable 82.

For controlling movement of the damper Operating motor 66 (see FIGURE4), I have shown an on and off push button switch 534 on the panel 75(see Pi URE 1). One motor terminal 65:: of the motor es is connecteddirectly to the source E through panel terminal 85a and cable 8%. Theother motor terminal 65b is connected indirectly to the other side ofthe source B through push button switch 84, panel terminal 855 and cable$6. Since the motor is a reduction gear type for relatively slow speedoperation, the amount of turning of the damper plate 52, can beaccurately governed by the time period.

Although for purposes of simplicity of illustration, 1 have shown amanual control for turning the plate 52 for controlling back pressurewith reference to the positive flow of hot gases from the open top endportion of the container 1 I also contemplate the use of an automaticpressure controller, such as the type 11036 disclosed in the Leeds andNorthrup catalog 177065 issue No. 3. In this connection, I will employ arecorder, such as disclosed in the catalog, either in place of or incombination with the pyrometer 72.

In carrying out an operation in accordance with my invention, about onethird or". the charge at the bottom of the container should comprisesome material, particularly where scrap metal is being used, that willabsorb the heat of the gas rapidly and at the same time allow it to passrcely. The remainder of the material or scrap need only be givenreasonable attention to avoid jamming which is similar to the practiceinvolved irr connection with cupola and blast furnace practice. Inaccordance with my present invention, I avoid the tendency of the hotgas to short circuit along the outside perimeter of the charge. Acontrollable rate of the heating medium is maintained at all times, inorder to get the heating started and at the best rate and to develop areasonable uniformiy of temerature throughout the charge.

A variable speed exhaust fan 48, such as previously mentioned, whichwill resist a temperature of 700 up to about 12 9 F, is satisfactory forpositively drawing off the gas from a flow opening at the top of thecontainer. Its control switch 8% is placed in a prominent position forready utilization. Means is associated with exhaust ducting connected tothe fiow opening for tempering the exhas-st gas with atmospheric gasbefore the gas reaches the exhaust fan to protect it from excessivetemperatures.

in employing my construction, I have been able to eliminate a swingingcran except for small foundries which have no available overhead crane.The body of the container Ittl should be lined with about 4 to 6 inchthickness (depending on diameter of the container) of dense hard andfirst class fire brick, such as used for ladle linin and which can bestresist scratching and erosion of scrap. The joints should be dipped andeach fitted to its neighbor. The hood id may be lined with asemirefractory cement of the l4OG F. classification.

As to the orifices of the grate 12, the special section portion a prvides for free entry of the heating gases and the portion b may beeasily enlarged by means of a thin emery wheel, as desired. This givesconsiderable tie);- ibility to the heat distribution value of thegrates, in that all of the orifices may be enlarged for greater heatingcapacity or certain of them in a given area may be enlarged to suit theload being handled. By employing a constant speed fan 48 in the exhaustfrom the container, having a suitable volumetric capacity depending onthe size of the heater, and capable of withstanding a temperature of notless than 700 F. and further, by properly controlling the butterflydamper 50, I have been able to completely control the heating operation.If desired, an air pressure gauge may be positioned in the conduit 45 toautomatically control the damper 59.

If a bolted connection is used between the flanges of the collar 43 andthe duct 45, at the end of each seat, the hood 4t? is swung aroundcarrying with it the duct and the pressure control (damper or valve5%)). This movement indicates that the control panel be located adjacentto the swinging gear column, if one is used.

By way of example, in operating the apparatus, a pair of heatingcontainer units B and their swing gates are checked to assure that allorifices are clear. Then each heater is charged, beginning with a bottomlayer of material representing the selected materials previouslydiscussed, with the rougher materials added vertically thereto. The hood4% is then swung into place and the constant speed fan motor is started.The butterfly valve Ed is at such time set at its fully open position.The burners 25 are previously lit to condition the containers and theiroperation is continued until the completion of the conditioning of thecharge material which is added thereto. At such time, the hood 49 isremoved from one container and such container is carried over, as by anoverhead crane, in alignment with the vertical axis of the open mouthportion of a melting furnace C which has been fitted with suitable hooksto engage the grates. The container unit B is then raised with respectto the furnace C to open its gates and charge the 13 pie-heated scrapmaterial through its open mouth portion. The container is thenimmediately returned to its initial position over the combustionchamber. The operation is then repeated as to the second container tocomplete the charging of the furnace.

The overall efliciency of the pre-heating is greatly increased bymaintaining an idling heat on the heater during the charging period, byimmediately returning the empty container to the heater, and bymaintaining a so-called idling temperature on the empty container up tothe time when it is again charged (recharged). This retains the heat ofthe walls and the lining and sets up important channels for the heatingmeans to pass through the charge or scrap mass as it is beingintroduced, as well as after it is completely charged, but before theexhaust fan takes over.

The interim idling step is important, not only in accomplishing thedesired type of full heat flow through the full charge, but also in moreefficiently and effectively bringing the charge up to full heat.Progressive portions of the charge are warmed as they are progressivelyintroduced with minimized heat load on the equipment. Difiicultiesincident to a cold charge are avoided, a better heat economy isattained, wear and tear on the equipment is minimized, and a desiredtype of heat flow through the charge is accomplished The idlingtemperature of the hot gas supplied by the heater A may correspond tothe full operating temperature, but is preferably slightly lower, forexample, in the neighborhood of 100 to 300 lower, Where the fulloperating temperature is about 1400 to 1500 F. I employ this sameprinciple in preliminarily heating the containers 10 up in starting theoperation; and, during the first charging of the metal materials, Imaintain the idling hot heating gas flow to set up proper flow channelsor passageways through the materials.

What I claim is: i

1. A method of preconditioning metal materials in the nature of scrap,sponge and briquettes within a conditioning chamber defined by the innerperiphery of an upwardly-projecting enclosing container having aswingable bottom grate for maintaining the materials in position thereinduring their conditioning and for thereafter charging the materials intoan open mouth of a melting furnace which comprises, inducing a velocityflow of hot gases uniformly upwardly through a central area of thebottom grate in an inwardly-spaced relation from the inner periphery ofthe container into the lower end of the conditioning chamber; flowingthe hot gases substantially uniformly upwardly along the conditioningchamber and out of the upper end of the container, while progressivelycharging the metal materials downwardly through the upper end of thecontainer along the conditioning chamber into a supported relation onthe grate until the chamber is fully charged with the materials, andwhile establishing flow channels for the hot gases through thematerials; then placing a hood over the upper end of thecontainer andapplying a controlled positive upward drawing-off force to the hot gasesthrough the hood, while maintaining an upward flow of the hot gasesalong the established flow channels through the materials until thematerials in the conditioning chamber are fully heated-up andconditioned; and finally, swinging the bottom grate to an open positionand directly charging the heated and conditioned materials into the openmouth of the melting furnace.

2. A method as defined in claim 1 wherein, the positive upwarddrawing-off force applied to the hot gases through the hood iscontrolled to maintain the grate Within a maximum temperature of about1550 F., to maintain the temperature of the hot gases within theconditioning chamber at about 1400 to 1450 'F., and to assure a maximumefficiency of utilization of the heat of the Cir 14 hot gases in heatingup and conditioning the material in the conditioning chamber.

3. A method as defined in claim 1 wherein the hot gases are introducedinto the conditioning chamber through a plurality of transverse rows oforifices in the grate that are spaced inwardly from the inner peripheryof the container, the control of the positive upward drawing-off forceapplied to the hot gases is accom plished by periodically taking meantemperature readings of the hot gases in the conditioning chamber andadjusting the size of a flow opening from the hood in accordancetherewith to maintain an elfective conditioning of the metal materialsand conserve the heat of the hot gases during the heating andconditioning of the materials, and the maximum temperature of the hotgases that are being flowed through the grate is controlled to preventdamage to the grate.

4. Apparatus for pro-conditioning metal charges in the nature of scrap,sponge and ore briquettes and for charging pro-conditioned metalmaterials into a melting furnace comprising, in combination, anelongated container having an open upper end for receiving the metalmaterials, having a heat-resistant wall defining an enclosing chamberfor conditioning the metal materials, and having an open lower end fordicsharging conditioned metal materials therefrom; a grate positioned onsaid container for opening and closing movement at the open lower endthereof to, when closed, define a retaining grate for supplyingconditioning heat to the metal materials in the enclosing chamber andto, when opened, discharge conditioned metal materials from the openlower end of said container into the melting furnace; ahot-gas-generating base unit having an open upper end for discharginghot gases upwardly therefrom and for removably-supporting the lower endof said container-thereon with said grate extending over the open upperend thereof to receive hot gases therefrom, said base unit having meansfor supplying the hot gases at a substantially uniform elevatedtemper'autre upwardly through said grate into the open lower end of saidcontainer; means removably connected to the open upper end of saidcontainer for positively drawing the hot gases from said base unitupwardly through said grate and for controlling the rate of withdrawalof the gases from the open upper end of the container, substantiallyuniformly through the metal materials within the enclosing chamber, andin a partially cooled condition out through the open upper end of saidcontainer; means for moving said container after the metal materialshave been conditioned within the enclosing chamber from said base unitinto an aligned position with the melting furnace, and means cooperatingwith said container for swinging said grate to an open position todischarge the conditioned metal materials into the melting furnace.

5. Apparatus for pre-conditioning metal charge materials in the natureof scrap, sponge and ore briquettes for introduction into an open mouthof a melting furnace which comprises, an elongated container having anopen upper end for receiving the metal'materials, having aheat-resistant wall defining an enclosing chamber for conditioning themetal materials, and having an open lower end for dischargingconditioned metal materials therefrom; a grate swingably positoned onsaid container for opening and closing movement at the open lower endthereof to, when closed, define a retaining grate for supplyingconditioning heat to the metal materials in the enclosing chamber andto, when opened, discharge conditioned metal materials from the openlower end of said container into'the melting furnace, means connected tosaid grate and operatively positioned on said container for opening andclosing said grate, and said means has portions tocentrally-c0operatively-align said container with and above the openmouth of the melting furnace before said grate is opened to dischargethe conditioned metal materials therein.

6. Apparatus for pre-conditioning metal charge materials in the natureof scrap, sponge and ore briquettes for introduction into a meltingfurnace which comprises, a vertically-elongated container having an opentop end for receiving the metal materials, having a heat resistant walldefining an enclosing chamber for conditioning the metal materials, andhaving an open lower end for discharging conditioned metal materialstherefrom; a partible grate, means swingably mounting said grate at theopen end of said container and normally biasing it towards a closingposition with respect to said container, means for supplyingconditioning heat up through said grate when it is in its closedposition for conditioning metal materials in the enclosing chamber; andoperating means carried by said container, operatively connected at oneend to said grate, and constructed for pulling movement at its oppositeend to open said grate against the normal closing bias of said firstmentioned means and discharge conditioned metal materials from saidcontainer into the melting furnace when said container has been movedinto alignment with tr e melting furnace.

7. Apparatus for processing metal charge materials in the nature ofscrap, sponge and ore briquettes for introduction into an open mouth ofand for melting in a furnace which comprises, a pro-conditioningcontainer having open upper and lower end portions and having aheat-resistant wall for receiving the metal charge materials andpre-conditioning them therein, a partibie grate swingaoly mounted onsaid container at the lower end portion thereof for movement betweenopen and closed positions with respect thereto, means for normallymaintaining said partible grate in a closed position, said grate havingfiow orifices therein to by-pass hot treating gases therethrough, anupwardly-open combustion-chamber-defining base having wall portions forremovably receiving and supporting said container when said partiblegrate is in its closed position and for supplying hot combustion gasesupwardly through said grate into said container to pre-condition themetal charge materials therein, means for positively drawing the hotgases upwardly along said container through the metal charge materialstherein and out of the open upper end portion of said container, andmeans for indicating and controlling the temperature of the hot gasesmoving through said grate to prevent ove heating of said grate and forindicating the mean temperature of the metal charge materials in saidcontainer and controlling the outflow or" the gases from the upper openend portion of said container to assure an efiective pro-conditioning ofthe metal charge materials within said container.

8. Apparatus for pie-conditioning metal materials in the nature ofscrap, sponge and ore briquettes for introduction into an open mouth ofa melting furnace which comprises, an upwardly-elongated containerhaving upper and lower open end portions and having heat-resistant wallsdefining an enclosing chamber for receiving metal charge materialstherein, a partible grate swingably mounted at the open lower endportion of said container to normally move to a closed position torreceiving the metal charge materials thereon, a hot-gas-generating basepositioned to removably receive the bottom end portion of said containerthereon and to supply hot treating gases up wardly through said grateinto said container and through the metal charge materials therein topro-condition them, means for lifting said container off said base afterthe pro-conditioning of the metal charge materials therein and formoving said container into a cooperating position with the open mouth ofthe melting furnace, and means carried by said container and cooperatingwith the melting furnace for centering the bottom end portion of saidcontainer above the open mouth of the furnace and for then swinging saidpartible grate to an open position to discharge the pro-conditionedmaterials into the melting furnace.

9. Apparatus for pro-conditioning metal ch -ge in terials in the storeof scrap, sponge and ore briquettes for introducing them whenpreconditioned into an open mouth of a melting furnace which comprises,a verticallyelongated conditioning container having an open lowe endportion and having a heat-resistant enclosing wall defining aconditioning chamber for the metal charge materials therein, a partiblegrate operatively carried by said container for swinging movementbetween a closed position with respect to the open end lower portion ofsaid container to support the metal charge materials therein and to anopen position to charge preconditioned metal materials into the openmouth of the furnace; at combustion-chamber-defining base forreceivably-supporting said container and said grate when said grate isin a closed position and for supplying hot conditioning gases throughsaid grate into the chamber of said container and up- Wardly through themetal charging materials therein for pre-conditioning them, said basehaving an outer wall defining a combustion chamber and acentraliy-projecting wall defining a central support for said grate,means for lifting said container and said grate off said base and into aposition above the open mouth or" the furnace, and means cooperatingwith said last-mentioned means for positively centrally aligning saidcontainer with and above the open mouth of the furnace and for swingingsaid partible grate into an open position to dischar e pie-conditionedmetal charge materials therein.

10. Apparatus for preconditioning metal charge materials in the natureof scrap, sponge and ore briquettes and for charging the pie-conditionedmetal materials into an open mouth or" a melting furnace whichcomprises, an elongated conditioning container having a heat-resistantwall defining a conditioning chamber for receiving the metal chargematerials therein and having an open lower end portion, a partiblegrate, means swingably mounting said grate on said container andbalancing said grate for normally maintaining it in a closing-oilposition with respect to the open lower end portion of said containerand for utilizing the weight or the charge materials to support themetal char e materials therein, means for conditioning the metal chargematerials within said container, and means associated with saidcontainer for opening said partible grate to discharge pro-conditionedmetal charge materials therefrom into the open mouth or" the meltingfurnace when said container has been removed from said base.

11. Apparatus as defined in claim 10 wherein said means for opening saidpartible grate comprises, swing arms carried by said container andoperatively connected to side portions of said grate, lifting lugsprojecting outwardly from end portions of said partible grate, and cablemeans operatively connected to said lifting lugs for swinging saidpartible grate outwardly on said container to ope it on said container,

12. Apparatus as defined in claim 19 wherein, lugs are carried by thefurnace, and said cable means is provided with means fordetachable-connection with said lastmentioncd lugs to open said gratewhen said container is lifted away from the furnace.

13. Apparatus for preconditioning metal charge materials in the natureof scrap, sponge and ore briquettes and for charging the pro-conditionedmetal materials into an open mouth of a melting furnace which comprisean elongated conditioning container having a heat-resistant Walldefining a conditioning chamber for receiving the metal charge materialstherein and having an open lower end portion, a partible grate, meansswingably mounting said grate on said container and balancing said gratefor normally maintaining it in a closing-off position with respect tothe open lower end portion of said container to support the metal chargematerials therein, said grate having a close -off outer peripheralflange portion that defines a closed-oft area about the inner peripheryof said container and also having a plurality of elongated Gnu 17 floworifices through its inner transverse portion to define a central areafor passing hot gases in velocity streams upwardly substantiallyuniformly into the conditioning chamber of said container and away fromouter peripheral portions of the charge materials in the chamber, a gasgenerating base for removably supporting said container and saidpartible grate and for supplying hot conditioning gases upwardly throughthe flow orifices of said grate into the conditioning chamber of saidcontainer through the metal charge materials therein forpre-conditioning them, and means associated with said container and themelting furnace for opening said partible grate to dischargepre-conditioned metal charge materials therefrom into the open mouth ofthe melting furnace when said container has been removed from said base.

References Cited by the Examiner UNITED STATES PATENTS Kaiser 29469DAVID L. RECK, Primary Examiner.

WINSTON A. DOUGLAS, Examiner.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION April 27, 1965Patent No. 3,180,724

Frank W. Brooke It is hereby certified that error appears in the abovenumbered patent requiring correction and that the said Letters Patentshould read as corrected below.

Column 12, line 51, for "seat" read heat Signed and sealed this 21st dayof September 1965.

(SEAL) Atlest:

EDWARD J. BRENNER ERNEST W. SWIDER Commissioner of Patents AtlcstingOfficer

1. A METHOD OF PRE-CONDITIONING METAL MATERIALS IN THE NATURE OF SCRAP,SPONGE AND BRIQUETTES WITHIN A CONDITIONING CHAMBER DEFINED BY THE INNERPERIPHERY OF AN UPWARDLY-PROJECTING ENCLOSING CONTAINER HAVING ASWINGABLE BOTTOM GRATE FOR MAINTAINING THE MATERIALS IN POSITION THEREINDURING THEIR CONDITIONING AND FOR THEREAFTER CHARGING THE MATERIALS INTOAN OPEN MOUTH OF A MELTING FURNACE WHICH COMPRISES, INDUCING A VELOCITYFLOW OF HOT GASES UNIFORMLY UPWARDLY THROUGH A CENTRAL AREA OF THEBOTTOM GRATE IN A INWARDLY-SPACED RELATION FROM THE INNER PERIPHERY OFTHE CONTAINER INTO THE LOWER END OF THE CONDITIONING CHAMBER; FLOWINGTHE HOT GASES SUBSTANTIALLY UNIFORMLY UPWARDLY ALONG THE CONDITIONINGCHAMBER AND OUT OF THE UPPER END OF THE CONTAINER, WHILE PROGRESSIVELYCHARGING THE METAL MATERIALS DOWNWARDLY THROUGH THE UPPER END OF THECONTAINER ALONG THE CONDITIONING CHAMBER INTO A SUPPORTED RELATION OFTHE GRATE UNTIL THE CHAMBER IS FULLY CHARGED WITH THE MATERIALS, ANDWHILE ESTABLISHING FLOW CHANNELS FOR THE HOT GASES THROUGH THEMATERIALS; THEN PLACING A HOOD OVER THE UPPER END OF THE CONTAINER ANDAPPLYING A CONTROLLED POSITIVE UPWARD DRAWING-OFF FORCE TO THE HOT GASESTHROUGH THE HOOD, WHILE MAINTIANING AN UPWARD FLOW OF THE HOT GASESALONG THE ESTABLISHED FLOW CHANNELS THROUGH THE MATERIALS UNTIL THEMATERIALS IN THE CONDITIONING CHAMBER ARE FULLY HEATED-UP ANDCONDITIONED; AND FINALLY, SWINGING THE BOTTOM GRATE TO AN OPEN POSITIONAND DIRECTLY CHARGINT THE HEATED AND CONDITIONED MATERIALS INTO THE OPENMOUTH OF THE MELTING FURNACE.